.sidebar {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    width: var(--sidebar-width);
    background: var(--bg-sidebar);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    z-index: 100;
    overflow: hidden;
    transition: width var(--transition-slow);
}

.sidebar-collapsed .sidebar {
    width: var(--sidebar-collapsed-width);
}

.sidebar-brand {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-6) var(--space-4) var(--space-4);
    font-weight: var(--weight-extrabold);
    font-family: var(--font-display);
    font-size: var(--title);
    color: var(--text-primary);
    letter-spacing: var(--tracking-tight);
    white-space: nowrap;
    overflow: hidden;
}

.sidebar-brand .brand-text {
    color: var(--text-primary);
}

.sidebar-brand .brand-icon {
    width: 24px;
    height: 24px;
    flex-shrink: 0;
    color: var(--accent-primary);
    font-size: 1.3rem;
    display: flex;
    align-items: center;
    justify-content: center;
}

.sidebar-collapsed .sidebar-brand {
    justify-content: center;
    padding: var(--space-6) 0 var(--space-4);
}

.sidebar-scroll {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
    padding: 0 var(--space-3);
}

.sidebar-section {
    margin-bottom: var(--space-6);
}

.sidebar-section-label {
    padding: 0 var(--space-2) var(--space-2);
    font-size: var(--xs);
    text-transform: uppercase;
    letter-spacing: var(--tracking-wide);
    color: var(--text-dim);
    font-weight: var(--weight-semibold);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.sidebar-collapsed .sidebar-section-label {
    display: none;
}

.sidebar-nav {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.sidebar-link {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-2) var(--space-2);
    border-radius: var(--radius-md);
    color: var(--text-muted);
    font-size: var(--body);
    font-weight: var(--weight-medium);
    white-space: nowrap;
    transition: background var(--transition), color var(--transition);
    position: relative;
}

.sidebar-link .link-icon {
    width: 20px;
    height: 20px;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0.7;
    transition: opacity var(--transition);
}

.sidebar-link .link-label {
    opacity: 1;
    transition: opacity var(--transition-slow);
    overflow: hidden;
}

.sidebar-collapsed .sidebar-link {
    justify-content: center;
    padding: var(--space-2) 0;
    margin: 0 auto;
    width: 44px;
    border-radius: var(--radius-lg);
}

.sidebar-collapsed .sidebar-link .link-label {
    width: 0;
    opacity: 0;
}

.sidebar-link:hover {
    background: var(--surface-bg-hover);
    color: var(--text-primary);
}

.sidebar-link:hover .link-icon {
    opacity: 1;
}

.sidebar-link.active {
    background: var(--surface-bg-active);
    color: var(--accent-primary);
}

.sidebar-link.active .link-icon {
    opacity: 1;
}

.sidebar-footer {
    margin-top: auto;
    padding: var(--space-2);
    border-top: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.sidebar-user {
    padding: var(--space-2) var(--space-2);
    font-size: var(--caption);
    color: var(--text-dim);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.sidebar-collapsed .sidebar-user {
    display: none;
}

.sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 99;
    animation: fade-in 0.2s ease-out;
}

@keyframes fade-in {
    from { opacity: 0; }
    to { opacity: 1; }
}

@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
        transition: transform var(--transition-slow);
    }

    .sidebar-open .sidebar {
        transform: translateX(0);
    }
}